The George Warren Brown School of Social Work at Washington University seeks an additional five years of support for a predoctoral and postdoctoral research training program focusing on services to, treatment of, and policies affecting populations vulnerable to substance use disorders and co-occurring and comorbid conditions. The Transdisciplinary Training in Addictions Research (TranSTAR) Program will provide a stimulating and collaborative research training environment that transcends disciplinary boundaries. It aims to produce a cadre of well-trained addictions researchers, with state-of-the-art knowledge of addictions services, delivered in non- specialty settings, and particularly targeted to underserved, vulnerable populations. TranSTAR embraces the paradigm that no single factor determines whether a person will become addicted as highlighted in a recent NIDA report (NIDA 2010, p. 8). Hence, TranSTAR emphasizes the importance of understanding protective and modifiable risk factors and co-occurring and co morbid conditions that inform, influence, and interact with drug use, abuse, dependence, and addictive behaviors. Trainees will acquire the necessary knowledge and skills to: (1) conceptualize meaningful research questions with practical implications for service delivery, policy, and applied research; (2) execute research projects using rigorous and cutting-edge methods; (3) create competitive grant applications; and (4) translate and disseminate results with potential for high impact. TranSTAR will provide: (a) transdisciplinary and specialized coursework and seminars, beyond required doctoral courses, taught by leading faculty in social work, public health, psychiatry, statistics, and the social sciences; (b) structured mentoring, advising, and hands-on experience, on funded addictions research projects through three predoctoral semesters of required research practice and in other semesters, research assistantships; (c) pilot study work groups and proposal critique review sessions; (d) predoctoral teaching assistantships in Master-level courses in addiction, comorbid conditions, statistics, and research methodology; (e) professional development sessions on presentation skills, effective communication of research findings, and soft-skills related to networking and effective collaborative team science; and (f) on-going, multi-faceted training in ethics and the responsible conduct of research. TranSTAR uses a three-tiered approach to on- going monitoring and evaluation of key program success indicators and achievement of milestones. We request funds for three predoctoral and two postdoctoral trainees per year to maintain a cohesive training cohort through the duration of training.